EP1000007B1 - Process for the production of aromatic acids - Google Patents

Process for the production of aromatic acids Download PDF

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EP1000007B1
EP1000007B1 EP97927191A EP97927191A EP1000007B1 EP 1000007 B1 EP1000007 B1 EP 1000007B1 EP 97927191 A EP97927191 A EP 97927191A EP 97927191 A EP97927191 A EP 97927191A EP 1000007 B1 EP1000007 B1 EP 1000007B1
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process according
zirconium
acetic acid
metal
oxidation
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EP1000007A1 (en
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Franco Codignola
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/16—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation
    • C07C51/21—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen
    • C07C51/255—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of compounds containing six-membered aromatic rings without ring-splitting
    • C07C51/265—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of compounds containing six-membered aromatic rings without ring-splitting having alkyl side chains which are oxidised to carboxyl groups

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  • the present invention relates to a new process for the production of mono- and poly-carboxylic aromatic acids by oxidation with molecular oxygen and/or air of aromatic compounds containing at least one oxidisable substituent group attached directly to the carbon atom of the corresponding aromatic ring.
  • oxidisable substituent group is to be understood as meaning any substituent in which a carbon atom is bonded directly to the aromatic ring and which, after oxidation, is converted into the COOH group, still bonded to the aromatic ring.
  • methyl, methylene, hydroxymethyl, hydroxymethylene, ketone and aldehyde groups are considered to be among the more interesting oxidisable groups.
  • aromatic compounds used as starting materials in the present invention are therefore those which possess one or more of the mentioned oxidisable groups.
  • each of these groups has to be separated from the others by at least one carbon atom of the unsubstituted aromatic ring.
  • the above-mentioned oxidation processes are carried out with oxygen and/or air in the presence of a catalyst.
  • the catalysts known from the literature and used industrially in oxidation reactions of the type indicated above normally contain cobalt salts as the main active element, together with other metals, such as, for example, manganese.
  • metals are usually used in the form of monocarboxylic aliphatic acid salts, preferably acetates, which are soluble in aqueous acetic acid, which is in fact the preferred solvent for aromatic compounds in this type of reaction.
  • the activators of the oxidation catalysts can be of either inorganic or organic character and perform the task of activating the oxidation reaction of the catalysts which can in turn be reduced during the oxidation of the aromatic compounds.
  • the activator used in the first process is bromine in its various forms, that is to say: molecular bromine, hydrobromic acid, bromides, etc.
  • the activating action of bromine takes place at temperatures higher than 180°C, normally from 200 to 225°C, and at pressures of approximately from 20 to 25 bar.
  • the corresponding apparatus has to be constructed with materials having a particular thermal resistance, such as titanium or its alloys, which involves a further increase in costs.
  • the second process uses acetaldehyde as the oxidation activator.
  • the acetaldehyde is oxidised to acetic acid with a yield of approximately 80%; the remaining acetaldehyde is, however, irretrievably burnt to CO 2 + H 2 O.
  • This oxidation in addition to involving a substantial waste of acetaldehyde, also has the disadvantage of substantially increasing the thermal charge of the reactor.
  • United States Patent No. 5,112,992 describes the use of metals of groups IIIA and IVA of the periodic table of elements, especially zirconium and hafnium, as activators of catalysts, for increasing the kinetics of the oxidation reactions in which catalytic complexes based on cobalt and manganese are used in the presence of bromine as activator.
  • the catalytic activity of zirconium and hafnium derives:
  • aromatic mono- and poly-carboxylic acids obtained by the processes specified above must then be purified by hydrogenation in aqueous solutions at elevated temperatures and pressures so that they can be used directly in the polycondensation installations used for the production of polymers having the most varied industrial uses (fibres, bottles and various containers, polyester resins, etc.).
  • the catalytic metals used in the process for the purification of the various crude aromatic carboxylic acids are palladium and rhodium supported on carbon or other inorganic supports resistant to the high temperatures of the purification process.
  • the purification process in its turn has a further disadvantage associated basically with the concentrations of zirconium and hafnium.
  • Zirconium and/or hafnium acetates once they have entered the purification reactor, tend to hydrolyse, precipitating as insoluble polymer oxides on the hydrogenation catalyst, with the consequent inactivation of the latter.
  • This result as described in the already mentioned United States Patent No. 5,112,992, can be avoided by limiting the concentration of the soluble salts of hafnium and zirconium in the initial reaction mixture to a value of not greater than 250 ppm, which inevitably limits the efficiency of the process.
  • GB-A1063964 discloses a process for the production of aromatic acids by catalytic oxidation of the corresponding aromatic precursor in presence of a catalyst system containing ZrO(OAc) 2 in combination with La(OAc) 3 ; this process affords yields of about 80% at an absolute reaction pressure higher than 20 bar.
  • EP-A0026507 relates to a process for preparing aromatic carboxylic acids by oxidation of the corresponding precursors in presence of a catalyst system consisting of cobalt octoate and zirconium octoate in absence of an aliphatic carboxylic acid.
  • the aim of the present invention is therefore to provide a new process for the production of mono- and poly-carboxylic aromatic acids for catalytic oxidation, which is free from all the disadvantages mentioned above.
  • a process has now surprisingly been found, and constitutes the subject-matter of the present invention, for the production of mono- and poly-carboxylic acids, wherein a compound selected from toluene, p-xylene, m-xylene, mesitylene, 2.6-dimethyl-naphtalene is oxidized with molecular oxygen and/or air in presence of a catalyst system in liquid homogeneous phase; said process being carried out in aqueous acetic acid, at a pressure of from atmospheric pressure to 5 bar, at a temperature of from 90 to 150° C and in absence of bromine and aldehydes; and said catalyst system consisting in a combination of (i) an acetate of a metal having a valence higher than 2 of group VIIIA of the periodic table of the elements and/or cerium acetate, and (ii) zirconium acetate.
  • the above-defined process is capable of catalysing almost completely the -oxidation, with molecular oxygen and/or air, of the mentioned aromatic compounds to give the corresponding aromatic acids without the necessity for the use of activators such as bromine or acetaldehyde, and without the necessity for the imposition of undue limitation on the concentrations of zirconium and/or hafnium.
  • the reaction for the oxidation of the above-defined aromatic compounds is carried out in liquid phase and with omogeneous catalysts, using an aqueous organic solvent, preferably aqueous acetic acid, as the solvent.
  • the metals used in the implementation of the present invention are preferably employed in the form of organic acid salts soluble in the reaction solvent, preferably acetates.
  • organic acid salts soluble in the reaction solvent
  • acetates preferably acetates.
  • the related precursor chemical compounds of those organic salts such as, for example, hydroxides, oxides, carbonates, etc., such as, for example, ruthenium oxide, which are able to react with the solvent used, forming the respective salts soluble therein.
  • the metals used in the reaction will generally be present in solution in the form of acetates.
  • the process forming the subject-matter of the present invention is not efficient in the case of adjacent oxidisable groups; this phenomenon is attributable to the chelation effect exerted on the metal ions, of which the catalytic action is thus inhibited, by adjacent carboxylic groups which are formed in the initial stage of the oxidation reaction.
  • the solvent is aqueous acetic acid, generally in a concentration variable from 85 to 98% by weight, preferably from 95 to 98% by weight.
  • the present invention is carried out at temperatures of from 90°C to 150°C, preferably from 105°C to 115°C.
  • the oxidising agent of the present invention is preferably air, which can optionally be enriched with oxygen.
  • the total reaction pressure can vary from atmospheric pressure to 20 bar, preferably from 2 to 5 bar.
  • the ratio of the metals of point A to the metals of point B can vary from 1:1 to 1:0.01, and is preferably 1:0.3.
  • the content of zirconium in the reaction mixture is approximately from 0.05 to 1 gram atom per gram mole of the aromatic compounds to be oxidised to the corresponding carboxylic acids.
  • the autoclave is heated to 95°C and pressurised with air until a pressure of 4 bar is reached.
  • the oxidation operation is carried out under the same conditions as in Example 1 except that the content of cerium acetate 1 + 1 ⁇ 2 H 2 O and of zirconium acetate is doubled.
  • Example 2 The procedure is as in Example 1, using instead of the cerium acetate 66 g of 100% ruthenium oxide in the hydrated form soluble in aqueous acetic acid.
  • the conversion yield is 87% while the theoretical yield is 95.5%.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)

Abstract

PCT No. PCT/EP97/03154 Sec. 371 Date Jun. 25, 1999 Sec. 102(e) Date Jun. 25, 1999 PCT Filed Jun. 14, 1997 PCT Pub. No. WO98/29378 PCT Pub. Date Jul. 9, 1998Process for producing mono- and poly-carboxylic aromatic acids by oxidation of the corresponding precursors with molecular oxygen and/or air in the presence of a catalytic complex formed by a combination of at least one metal selected from ruthenium, iridium, platinum and palladium, and/or at least one metal of Group VIIA, principally rhenium; and/or cerium, and B at least one metal belonging IVA of the periodic table of elements, principally zirconium and/or hafnium.

Description

The present invention relates to a new process for the production of mono- and poly-carboxylic aromatic acids by oxidation with molecular oxygen and/or air of aromatic compounds containing at least one oxidisable substituent group attached directly to the carbon atom of the corresponding aromatic ring.
The term "oxidisable substituent group" is to be understood as meaning any substituent in which a carbon atom is bonded directly to the aromatic ring and which, after oxidation, is converted into the COOH group, still bonded to the aromatic ring.
The methyl, methylene, hydroxymethyl, hydroxymethylene, ketone and aldehyde groups are considered to be among the more interesting oxidisable groups.
The aromatic compounds used as starting materials in the present invention are therefore those which possess one or more of the mentioned oxidisable groups.
In order better to illustrate the invention, there will be indicated hereinafter, purely by way of non-limiting example, some of the possible oxidations which can be carried out with the present invention:
Figure 00010001
Figure 00010002
Figure 00010003
Figure 00020001
Figure 00020002
Figure 00020003
Figure 00020004
Figure 00020005
Figure 00020006
In particular, where there are two or more oxidisable groups, each of these groups has to be separated from the others by at least one carbon atom of the unsubstituted aromatic ring. With the process of the present invention it is thus not possible to oxidise o-xylene to phthalic acid, or 1,2-dimethylnaphthalene to 1,2-dinaphthoic acid.
According to the prior art, the above-mentioned oxidation processes are carried out with oxygen and/or air in the presence of a catalyst.
The catalysts known from the literature and used industrially in oxidation reactions of the type indicated above normally contain cobalt salts as the main active element, together with other metals, such as, for example, manganese.
These metals are usually used in the form of monocarboxylic aliphatic acid salts, preferably acetates, which are soluble in aqueous acetic acid, which is in fact the preferred solvent for aromatic compounds in this type of reaction.
However, both catalysts based only on the cobalt salt and bimetal catalysts have a disadvantage of not inconsiderable importance; they can oxidise only partially the oxidisable groups of the aromatic compounds in question.
In order to obtain complete oxidation, it is necessary to integrate the catalyst with suitable activators, which clearly involves per se an increase in the operating costs.
The activators of the oxidation catalysts can be of either inorganic or organic character and perform the task of activating the oxidation reaction of the catalysts which can in turn be reduced during the oxidation of the aromatic compounds.
The use of activators of the first type, rather than the second, leads to two distinct oxidation processes.
The activator used in the first process is bromine in its various forms, that is to say: molecular bromine, hydrobromic acid, bromides, etc. The activating action of bromine, however, takes place at temperatures higher than 180°C, normally from 200 to 225°C, and at pressures of approximately from 20 to 25 bar. Given the high operating temperatures, the corresponding apparatus has to be constructed with materials having a particular thermal resistance, such as titanium or its alloys, which involves a further increase in costs.
The second process, however, uses acetaldehyde as the oxidation activator. In the course of the reaction, the acetaldehyde is oxidised to acetic acid with a yield of approximately 80%; the remaining acetaldehyde is, however, irretrievably burnt to CO2 + H2O. This oxidation, in addition to involving a substantial waste of acetaldehyde, also has the disadvantage of substantially increasing the thermal charge of the reactor.
The conversion of acetaldehyde into acetic acid is also a rather negative economic phenomenon, given that the cost of acetaldehyde is higher than that of acetic acid and the increase in weight from acetaldehyde to acetic acid is not sufficient to cancel the difference in cost.
United States Patent No. 5,112,992 describes the use of metals of groups IIIA and IVA of the periodic table of elements, especially zirconium and hafnium, as activators of catalysts, for increasing the kinetics of the oxidation reactions in which catalytic complexes based on cobalt and manganese are used in the presence of bromine as activator.
The catalytic activity of zirconium and hafnium derives:
  • from the ability of their ions to reach a coordination number higher than 6, which increases and maintains the ratio of the number of ions having higher valencies to those having lower valencies in multivalent catalytic metals.
  • from the fact that the ions of zirconium and hafnium have stable valencies which do not interfere with the oxido-reduction kinetics of the ions of multivalent metals.
  • from the fact that the presence of the ions of zirconium and/or hafnium reduces the formation of dimers of multivalent catalytic metals which are normally less active than monomers.
The aromatic mono- and poly-carboxylic acids obtained by the processes specified above must then be purified by hydrogenation in aqueous solutions at elevated temperatures and pressures so that they can be used directly in the polycondensation installations used for the production of polymers having the most varied industrial uses (fibres, bottles and various containers, polyester resins, etc.).
The catalytic metals used in the process for the purification of the various crude aromatic carboxylic acids are palladium and rhodium supported on carbon or other inorganic supports resistant to the high temperatures of the purification process.
The purification process in its turn has a further disadvantage associated basically with the concentrations of zirconium and hafnium. Zirconium and/or hafnium acetates, once they have entered the purification reactor, tend to hydrolyse, precipitating as insoluble polymer oxides on the hydrogenation catalyst, with the consequent inactivation of the latter. This result, as described in the already mentioned United States Patent No. 5,112,992, can be avoided by limiting the concentration of the soluble salts of hafnium and zirconium in the initial reaction mixture to a value of not greater than 250 ppm, which inevitably limits the efficiency of the process.
GB-A1063964 discloses a process for the production of aromatic acids by catalytic oxidation of the corresponding aromatic precursor in presence of a catalyst system containing ZrO(OAc)2 in combination with La(OAc)3; this process affords yields of about 80% at an absolute reaction pressure higher than 20 bar. EP-A0026507 relates to a process for preparing aromatic carboxylic acids by oxidation of the corresponding precursors in presence of a catalyst system consisting of cobalt octoate and zirconium octoate in absence of an aliphatic carboxylic acid.
The aim of the present invention is therefore to provide a new process for the production of mono- and poly-carboxylic aromatic acids for catalytic oxidation, which is free from all the disadvantages mentioned above.
A process has now surprisingly been found, and constitutes the subject-matter of the present invention, for the production of mono- and poly-carboxylic acids, wherein a compound selected from toluene, p-xylene, m-xylene, mesitylene, 2.6-dimethyl-naphtalene is oxidized with molecular oxygen and/or air in presence of a catalyst system in liquid homogeneous phase; said process being carried out in aqueous acetic acid, at a pressure of from atmospheric pressure to 5 bar, at a temperature of from 90 to 150° C and in absence of bromine and aldehydes; and said catalyst system consisting in a combination of (i) an acetate of a metal having a valence higher than 2 of group VIIIA of the periodic table of the elements and/or cerium acetate, and (ii) zirconium acetate.
It has surprisingly been found that the above-defined process is capable of catalysing almost completely the -oxidation, with molecular oxygen and/or air, of the mentioned aromatic compounds to give the corresponding aromatic acids without the necessity for the use of activators such as bromine or acetaldehyde, and without the necessity for the imposition of undue limitation on the concentrations of zirconium and/or hafnium.
The reaction for the oxidation of the above-defined aromatic compounds is carried out in liquid phase and with omogeneous catalysts, using an aqueous organic solvent, preferably aqueous acetic acid, as the solvent.
The metals used in the implementation of the present invention are preferably employed in the form of organic acid salts soluble in the reaction solvent, preferably acetates. Alternatively, it is possible to use the related precursor chemical compounds of those organic salts, such as, for example, hydroxides, oxides, carbonates, etc., such as, for example, ruthenium oxide, which are able to react with the solvent used, forming the respective salts soluble therein.
Since aqueous acetic acid is the preferred solvent, the metals used in the reaction will generally be present in solution in the form of acetates.
As already mentioned above, the process forming the subject-matter of the present invention is not efficient in the case of adjacent oxidisable groups; this phenomenon is attributable to the chelation effect exerted on the metal ions, of which the catalytic action is thus inhibited, by adjacent carboxylic groups which are formed in the initial stage of the oxidation reaction.
The solvent is aqueous acetic acid, generally in a concentration variable from 85 to 98% by weight, preferably from 95 to 98% by weight.
In view of the fact that the activity of zirconium appears to decrease as the temperature of the reaction for the oxidation of the aromatic hydrocarbons increases, the present invention is carried out at temperatures of from 90°C to 150°C, preferably from 105°C to 115°C.
Thus, by operating at relatively moderate temperatures, at least relative to the 100 - 275°C indicated in United States Patent No. 5,112,592, and with an especially limited content of water in the reaction environment, it is possible to use concentrations of zirconium acetate higher than 250 ppm, the hydrolysis of the same preventing the consequent precipitation of the corresponding insoluble oxides.
The oxidising agent of the present invention is preferably air, which can optionally be enriched with oxygen.
The total reaction pressure can vary from atmospheric pressure to 20 bar, preferably from 2 to 5 bar.
The ratio of the metals of point A to the metals of point B can vary from 1:1 to 1:0.01, and is preferably 1:0.3.
It is also preferable for the content of zirconium in the reaction mixture to be approximately from 0.05 to 1 gram atom per gram mole of the aromatic compounds to be oxidised to the corresponding carboxylic acids.
The following examples will better explain the features of the present invention without thereby limiting the field of application thereof.
Example 1
There are charged into a 6-litre autoclave equipped with a turbine agitator, an air inlet, an air outlet with a trap cooled to -15°C:
Acetic acid 4% H2O 4,000 g
m-xylene 980 g
Cerium acetate 1+ ½ H2O 170 g
Zirconium acetate 12 g
The autoclave is heated to 95°C and pressurised with air until a pressure of 4 bar is reached.
After approximately 1 hour, the absorption of oxygen starts. After 5 hours, the absorption of oxygen is practically zero. The conversion yield is approximately 72% while the theoretical yield, taking into account the m-xylene removed from the air and condensed in the trap at the outlet of the autoclave, of m-toluic acid and 3-carboxybenzaldehyde present in the mother liquors is greater than 92%.
It should also be borne in mind that the reduction period of 1 hour is of no importance in a plant with total recycling of the mother liquors, where the mixture entering the oxidation reactor is already in the active state.
Example 2
The oxidation operation is carried out under the same conditions as in Example 1 except that the content of cerium acetate 1 + ½ H2O and of zirconium acetate is doubled.
The conversion yield increases to 95.5% while the theoretical yield is 94.5%.
Example 3
The procedure is as in Example 1, using p-xylene instead of m-xylene.
Conversion yield 82%, theoretical yield 94.5%.
Example 4
The procedure is as in Example 2, using p-xylene instead of m-xylene.
Conversion yield 86.5%, theoretical yield 95%.
Example 5
The procedure is as in Example 1, using instead of the cerium acetate 66 g of 100% ruthenium oxide in the hydrated form soluble in aqueous acetic acid.
The conversion yield is 87% while the theoretical yield is 95.5%.
Example 6
The procedure is as in Example 5, using p-xylene instead of m-xylene.
Conversion yield 88%, theoretical yield 96%.
Example 7
The procedure is as in Example 1, using 2,6-dimethylnaphthalene instead of m-xylene.
Conversion yield 70%, theoretical yield 93%.
Example 8
The procedure is as in Example 2, using 2,6-dimethylnaphthalene instead of m-xylene.
Conversion yield 75%, theoretical yield 93%.

Claims (11)

  1. A process for the production of mono- and poly-carboxylic acids, wherein a compound selected from toluene, p-xylene, m-xylene, mesitylene, 2,6-dimethyl-naphtalene is oxidized with molecular oxygen and/or air in presence of a catalyst system in liquid homogeneous phase; said process being carried out in aqueous acetic acid, at a pressure of from atmospheric pressure to 5 bar, at a temperature of from 90 to 150° C and in absence of bromine and aldehydes; and said catalyst system consisting in a combination of (i) an acetate of a metal having a valence higher than 2 of group VIIIA of the periodic table of the elements and/or cerium acetate, and (ii) zirconium acetate.
  2. A process according to claim 1 wherein said metal of group VIIIA is selected among ruthenium, iridium, platinum and palladium.
  3. A process according to claim 1 wherein the aqueous acetic acid is used in a concentration comprised between 85 and 98% by weight.
  4. A process according to claim 7 wherein the aqueous acetic acid is used in a concentration comprised between 95 and 98% by weight.
  5. A process according to claim 1 wherein the oxidation reaction is carried out at a temperature of 105-115° C.
  6. A process according to claims 1 wherein the oxidation reaction is carried out at a pressure of 2-5 bar.
  7. A process according to claim 1 wherein the weight ratio between the metal of point (i) and zirconium is comprised between 1:1 and 1:0.01.
  8. A process according to claim 7 wherein said weight ratio is 1:0.3.
  9. A process according to claim 1 wherein the amount in the reaction mixture of zirconium is of 0.05-1 gram atom/gram mole of the aromatic compounds to be oxidized to the corresponding carboxy acids.
  10. A process according to claim 1 wherein said acetates are introduced into the reaction mixture in the form of the corresponding chemical precursors which can react with the reaction solvent, thus giving place to the acetates themselves.
  11. A process according to claim 10 wherein said chemical precursor compounds are selected among the corresponding hydroxide, oxides, carbonates.
EP97927191A 1996-12-27 1997-06-14 Process for the production of aromatic acids Expired - Lifetime EP1000007B1 (en)

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ITMI962753 1996-12-27
IT96MI002753A IT1289529B1 (en) 1996-12-27 1996-12-27 PROCEDURE FOR THE PRODUCTION OF AROMATIC ACIDS
PCT/EP1997/003154 WO1998029378A1 (en) 1996-12-27 1997-06-14 Process for the production of aromatic acids

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Families Citing this family (15)

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IT1311976B1 (en) 1999-03-25 2002-03-22 Franco Codignola PROCEDURE FOR THE PRODUCTION OF AROMATIC ACIDS.
IT1312536B1 (en) * 1999-04-16 2002-04-22 Franco Codignola PROCEDURE FOR THE PRODUCTION AND PURIFICATION OF AROMATIC ACIDS.
CN1207259C (en) 2000-01-18 2005-06-22 因卡国际公司 Oxidation of alkyl aromatic compounds to aromatic acids in an aqueous medium
US6747171B2 (en) * 2000-02-03 2004-06-08 Bp Corporation North America Inc. Low temperature purification of naphthalene dicarboxylic acids
IT1319169B1 (en) 2000-07-14 2003-09-26 Eurotecnica Dev & Licensing Sr PROCEDURE FOR THE PURIFICATION OF AROMATIC CARBOXYLIC ACIDS.
US6657068B2 (en) 2002-03-22 2003-12-02 General Electric Company Liquid phase oxidation of halogenated ortho-xylenes
US6649773B2 (en) 2002-03-22 2003-11-18 General Electric Company Method for the manufacture of halophthalic acids and anhydrides
US6657067B2 (en) 2002-03-22 2003-12-02 General Electric Company Method for the manufacture of chlorophthalic anhydride
US7541489B2 (en) 2004-06-30 2009-06-02 Sabic Innovative Plastics Ip B.V. Method of making halophthalic acids and halophthalic anhydrides
US7550627B2 (en) * 2005-03-08 2009-06-23 Eastman Chemical Company Processes for producing aromatic dicarboxylic acids
US20060205974A1 (en) * 2005-03-08 2006-09-14 Lavoie Gino G Processes for producing aromatic dicarboxylic acids
CN101437610A (en) * 2006-05-08 2009-05-20 Bp北美公司 Process for the production of aromatic carboxylic acids in water
WO2008137491A1 (en) * 2007-05-04 2008-11-13 Bp Corporation North America Inc. Process and catalyst for oxidizing aromatic compounds
WO2015004683A2 (en) * 2013-07-12 2015-01-15 Reliance Industries Limited An integrated process for carboxylation and oxtoation ofalkyl substituted aromatic hydrocarbons
US9604896B2 (en) * 2014-09-03 2017-03-28 Eastman Chemical Company Halogen-free catalyst system and method for producing benzoic acid

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB831902A (en) * 1957-08-23 1960-04-06 Ici Ltd Improvements in and relating to a process for the production of terephthalic acid
JPS5136258B1 (en) * 1963-04-02 1976-10-07
NL140508C (en) * 1963-05-01
US3562318A (en) * 1966-11-10 1971-02-09 Petro Tex Chem Corp Catalytic oxidation process of mono-aryl compounds
NL7906575A (en) * 1979-09-01 1981-03-03 Stamicarbon PROCESS FOR PREPARING AROMATIC CARBONIC ACIDS.
US4992579A (en) * 1989-12-18 1991-02-12 Amoco Corporation Process for the production of trimellitic acid
CA2050866A1 (en) * 1990-09-10 1992-03-11 George F. Schaefer Oxidation of dialkyl polyaromatics to dicarboxypolyaromatics
FR2709432B1 (en) * 1993-09-03 1995-10-20 Elf Aquitaine Catalysts based on metallic oxides, with high dispersion, comprising in particular zirconia, their manufacture and their applications.

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US6670502B1 (en) 2003-12-30
ATE222581T1 (en) 2002-09-15
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